WO2019224946A1

WO2019224946A1 - Grid body and lead-acid battery

Info

Publication number: WO2019224946A1
Application number: PCT/JP2018/019852
Authority: WO
Inventors: 田中　伸和; 寺田　正幸
Original assignee: 日立化成株式会社
Priority date: 2018-05-23
Filing date: 2018-05-23
Publication date: 2019-11-28
Also published as: JPWO2019224946A1; JP7185981B2

Abstract

A grid body used as an electrode plate for a lead-acid battery and containing lead, said grid body comprising: a first surface and a second surface parallel to each other; and a plurality of through-holes penetrating through the first surface and the second surface, wherein the opening area of at least one of the plurality of through-holes on the first surface is different from the opening area thereof on the second surface.

Description

Grid and lead-acid battery

The present invention relates to a lattice body and a lead storage battery.

Lead storage batteries are widely used for industrial and consumer use because of their reliability and low price. In particular, there is a great demand for lead storage batteries for automobiles (so-called batteries).

Patent Document 1 describes a lead storage battery including a positive electrode plate and a negative electrode plate. In this lead storage battery, each of the positive electrode plate and the negative electrode plate is configured by filling a lead alloy lattice body with an active material. Then, the positive electrode plate and the negative electrode plate are alternately laminated via the separator, and the current collecting portions of the positive electrode plate and the negative electrode plate are collectively welded to the strap for each polarity, and the inter-cell connection portion or the pole column is connected to the strap. The electrode plate group is configured.

JP 2012-230838 A

By the way, in recent automobiles, since the number of electrical components has increased, the load on the battery has increased. As a result, the discharge amount of the battery is increased. As an index of the discharge amount of the battery, there is a discharge depth DOD (Depth of Discharge). The discharge depth DOD indicates that the discharge amount increases as the value increases. When the battery is charged / discharged under a condition where the DOD is large, mudification (softening phenomenon) in which the connection between the active materials weakens in the positive electrode plate, and the active material gradually drops from the lattice. In addition, since lead-acid batteries mounted on automobiles are exposed to large vibrations for a long time, the active material falls off from the lattice body. When the active material falls off from the lattice body, there arises a problem that the life of the electrode plate (particularly the positive electrode plate) is shortened.

Therefore, an object of one aspect of the present invention is to provide a lattice body and a lead-acid battery that can prevent the active material from falling off.

A grid body according to one aspect of the present invention is a grid body containing lead used for an electrode plate of a lead storage battery, and penetrating through a first surface and a second surface parallel to each other, and a first surface and a second surface. The opening area in the first surface and the opening area in the second surface are different in at least one of the plurality of through holes.

In this grid, when used for the electrode plate of a lead storage battery, the active material is held in the first surface, the second surface, and the plurality of through holes, but the first surface and the second surface are parallel to each other. Therefore, the active material tends to fall off from the first surface and the second surface. However, in at least one of the plurality of through holes penetrating the first surface and the second surface, since the opening area on the first surface and the opening area on the second surface are different, the active material is less likely to drop out of the through hole. . Thereby, falling off of the active material can be suppressed.

In all of the plurality of through holes, the opening area on the first surface and the opening area on the second surface may be different. In this lattice body, since the opening area on the first surface and the opening area on the second surface are different in all of the plurality of through holes, it is possible to further suppress the falling off of the active material.

In all of the plurality of through holes, the opening area on the first surface may be larger than the opening area on the second surface. In this lattice body, since the opening area on the first surface is larger than the opening area on the second surface in all of the plurality of through holes, the lattice body can be easily formed and the active material can be formed from the first surface side. Filling the active material into the lattice body is improved.

The total opening area of the plurality of through holes on the first surface may be larger than the total opening area of the plurality of through holes on the second surface. In this lattice body, since the total opening area of the plurality of through holes on the first surface is larger than the total opening area of the plurality of through holes on the second surface, the active material is less likely to fall out of the through holes as a whole.

A recess may be formed on at least one inner wall surface of the plurality of through holes. In this lattice body, since the recess is formed in at least one inner wall surface of the plurality of through holes, the active material enters the recess. Thereby, it can further suppress that an active material falls off.

) Concave portions may be formed on all inner wall surfaces of the plurality of through holes. In this lattice body, since the recesses are formed in all the inner wall surfaces of the plurality of through holes, the active material enters the recesses. Thereby, it can further suppress that an active material falls off.

At least one of the plurality of through holes may have a first tapered portion that reaches the first surface while expanding, and a second tapered portion that reaches the second surface while expanding. In this lattice body, since each of the plurality of through holes has the first tapered portion and the second tapered portion, the active material filled in the through holes has a shape spreading on both sides of the first surface and the second surface. That is, the active material has a shape that sandwiches the lattice from both sides of the first surface and the second surface. For this reason, it can further suppress that an active material falls.

Each of the plurality of through holes may have a first tapered portion that reaches the first surface while expanding, and a second tapered portion that reaches the second surface while expanding. In this lattice body, since each of the plurality of through holes has the first tapered portion and the second tapered portion, the active material filled in the through holes has a shape spreading on both sides of the first surface and the second surface. That is, the active material has a shape that sandwiches the lattice from both sides of the first surface and the second surface. For this reason, it can further suppress that an active material falls.

In the lead storage battery according to one aspect of the present invention, any of the above-described lattice bodies is used as at least one of the positive electrode plate and the negative electrode plate. In this lead storage battery, any one of the above-described lattice bodies is used as at least one of the positive electrode plate and the negative electrode plate, so that the active material can be prevented from falling off.

By the way, in the positive electrode grid, mudification (softening phenomenon) in which the connection between the active materials is weakened by repeated charging and discharging progresses. For this reason, the grid body may be a positive electrode grid body used for the positive electrode plate. Thereby, it can suppress efficiently that an active material falls.

According to the present invention, the active material can be prevented from falling off.

It is a perspective view showing the whole lead-acid battery structure and internal structure concerning one embodiment. It is a perspective view which shows the electrode group of the lead acid battery shown in FIG. It is a front view which shows a positive electrode plate (negative electrode plate). FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a front view showing a lattice object concerning one embodiment. It is a schematic cross section which shows a part of lattice body shown in FIG. It is a schematic cross section which shows a part of lattice body of a modification. It is a schematic cross section which shows a part of lattice body of a modification. It is a schematic cross section which shows a part of lattice body of a modification.

Hereinafter, preferred embodiments of a lead storage battery according to one aspect of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals. The numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In addition, “A or B” may include either one of A and B, or may include both.

<Lead battery>
FIG. 1 is a perspective view showing the overall configuration and internal structure of a lead storage battery 1 according to an embodiment. As shown in FIG. 1, the lead storage battery 1 includes a battery case 2 whose top surface is open and a lid 3 that closes the opening of the battery case 2. The battery case 2 and the lid 3 are made of, for example, polypropylene. The lid 3 is provided with a positive electrode terminal 4, a negative electrode terminal 5, and a liquid port plug 6 that closes a liquid injection port provided in the lid 3.

Inside the battery case 2, there are an electrode group 7, a positive pole 8 connecting the electrode group 7 to the positive terminal 4, a negative pole (not shown) connecting the electrode group 7 to the negative terminal 5, dilute sulfuric acid, etc. The electrolyte solution is accommodated.

FIG. 2 is a perspective view showing the electrode group 7. As shown in FIG. 2, the electrode group 7 includes a positive electrode plate 9, a negative electrode plate 10, and a separator 11 disposed between the positive electrode plate 9 and the negative electrode plate 10.

FIG. 3 is a front view showing the positive electrode plate 9 (negative electrode plate 10), and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. As shown in FIGS. 3 and 4, the positive electrode plate 9 includes a positive electrode grid (positive electrode current collector) 12 and a positive electrode active material (positive electrode material) 13. The positive electrode grid body 12 is a grid body of the positive electrode plate 9, and includes a grid portion 12a and an ear portion 12b that is integrated with the grid portion 12a and protrudes from one end of the grid portion 12a. The positive electrode active material 13 is an active material of the positive electrode plate 9 and is held by the positive electrode lattice body 12. The negative electrode plate 10 includes a negative electrode grid (negative electrode current collector) 14 and a negative electrode active material (negative electrode material) 15. The negative electrode lattice body 14 is a lattice body of the negative electrode plate 10, and includes a lattice portion 14a and an ear portion 14b that is integrally formed with the lattice portion 14a and protrudes from one end of the lattice portion 14a. The negative electrode active material 15 is an active material of the negative electrode plate 10 and is held by the negative electrode lattice body 14. The positive electrode grid body 12 and the negative electrode grid body 14 are formed of a lead alloy. The lead alloy may be an alloy containing tin, calcium, antimony, selenium, silver, bismuth and the like in addition to lead. Specifically, for example, an alloy containing lead, tin and calcium (Pb-Sn) -Ca alloy).

The electrode group 7 has a structure in which a plurality of positive electrode plates 9 and negative electrode plates 10 are alternately stacked in a direction substantially parallel to the opening surface of the battery case 2 via separators 11. That is, the positive electrode plate 9 and the negative electrode plate 10 are arranged so that their main surfaces extend in a direction perpendicular to the opening surface of the battery case 2. In the electrode group 7, the ears 12 b of the positive electrode grid bodies 12 of the plurality of positive electrode plates 9 are collectively welded by the positive side strap 16. Similarly, the ears 14 b of the negative electrode grid bodies 14 in the negative electrode plates 10 are collectively welded by the negative electrode side strap 17. The positive side strap 16 and the negative side strap 17 are connected to the positive terminal 4 and the negative terminal 5 through the positive pole 8 and the negative pole, respectively.

Then, the manufacturing method of the lead acid battery 1 is demonstrated. The method for manufacturing the lead storage battery 1 includes an electrode plate manufacturing process for obtaining the electrode plates (the positive electrode plate 9 and the negative electrode plate 10) and an assembly process for obtaining the lead storage battery 1 by assembling the components including the electrode plates.

In the electrode plate manufacturing process, for example, for each of the positive electrode plate 9 and the negative electrode plate 10, the electrode material paste (the negative electrode material paste and the positive electrode material paste) is held in the lattice body (the positive electrode lattice body 12 and the negative electrode lattice body 14) ( After filling, an unformed electrode plate is obtained by aging and drying.

The positive electrode material paste is obtained, for example, by adding an additive (reinforcing short fiber, etc.) and water to a raw material of the positive electrode active material (lead powder, red lead (Pb3O4), etc.) and then kneading with dilute sulfuric acid. It is done. After this positive electrode material paste is held (filled) in the positive electrode grid 12, it is aged for 15 to 60 hours in an atmosphere having a temperature of 35 to 85 ° C. and a humidity of 50 to 98 RH%, and is heated at a temperature of 45 to 80 ° C. for 15 to 15 hours. By drying for 30 hours, an unformed positive electrode plate is obtained.

The negative electrode material paste is, for example, dry by adding an additive (carbon material, barium sulfate, reinforcing short fiber, resin having a sulfone group and / or a sulfonate group, etc.) to the raw material of the negative electrode active material (lead powder or the like). After obtaining a mixture by mixing, it is obtained by adding dilute sulfuric acid and water and kneading. After this negative electrode material paste is held (filled) on the current collector, for example, it is aged for 15 to 30 hours in an atmosphere at a temperature of 45 to 65 ° C. and a humidity of 70 to 98 RH%, and then at a temperature of 45 to 60 ° C. for 15 to 30 By drying for a time, an unformed negative electrode plate is obtained.

In the assembling process, for example, an unformed negative electrode plate and an unformed positive electrode plate are alternately stacked via the separator 11, and the ear portions 12 b of the positive electrode grid 12 are connected (welded or the like) with the positive strap 16. At the same time, the ears 14 b of the negative electrode grid 14 are connected (welded or the like) by the negative strap 17 to obtain the electrode group 7. This electrode group 7 is arranged in the battery case 2 to produce an unformed battery. Next, after injecting an electrolytic solution (dilute sulfuric acid or the like) into an unformed battery, a direct current is applied to form a battery case. The lead acid battery 1 is obtained by adjusting the specific gravity of the electrolytic solution after the formation to an appropriate specific gravity.

Chemical conversion conditions and specific gravity of sulfuric acid can be adjusted according to the properties of the electrode active material. Instead of being performed after the assembly process, the chemical conversion treatment may be performed by immersing a large number of electrode plates after aging and drying in the electrode plate manufacturing process into a chemical conversion tank (tank conversion).

<Lattice>
Next, the positive electrode grid body 12 and the negative electrode grid body 14 used for the positive electrode plate 9 and the negative electrode plate 10 of the lead storage battery 1 described above will be described in more detail. In the present embodiment, since the positive electrode lattice body 12 and the negative electrode lattice body 14 have basically the same shape, the positive electrode lattice body 12 and the negative electrode lattice body 14 will be described together as the lattice body 21 below.

FIG. 5 is a front view showing a lattice body according to an embodiment. FIG. 6 is a schematic cross-sectional view showing a part of the lattice shown in FIG. As shown in FIGS. 3 to 6, the lattice body 21 (the positive electrode lattice body 12 and the negative electrode lattice body 14) is formed integrally with the lattice portion 22 (the lattice portion 12a and the lattice portion 14a) and the lattice portion 22. It has the ear | edge part 23 (ear part 12b and the ear | edge part 14b) which protruded from the end of the part 22. FIG. Note that the lattice body 21 corresponds to each of the positive electrode lattice body 12 and the negative electrode lattice body 14, the lattice portion 22 corresponds to each of the lattice portion 12a and the lattice portion 14a, and the ear portion 23 corresponds to the ear portion 12b and the ear portion. This corresponds to each of the parts 14b.

The lattice portion 22 is formed in a substantially rectangular thin plate shape, and includes a first surface 22a and a second surface 22b that are parallel to each other, and a plurality of through holes 22c that penetrate the first surface 22a and the second surface 22b. I have. For this reason, when the lattice part 22 is used for the electrode plate (the positive electrode plate 9 and the negative electrode plate 10) of the lead storage battery 1, the active material (the positive electrode active material 13 and the negative electrode active material 15) is the first surface of the lattice part 22. 22a, the second surface 22b, and the plurality of through holes 22c. In addition, an active material is not hold | maintained at the upper part (upper part of the 1st surface 22a and the 2nd surface 22b) of the grating | lattice part 22. FIG. There is no distinction between the first surface 22a and the second surface 22b, and either surface of the lattice portion 22 may be the first surface 22a or the second surface 22b. The number, shape, size, and the like of the through holes 22c formed in the lattice portion 22 are not particularly limited, and are set as appropriate as long as the active material can be appropriately retained.

In the lattice part 22, the opening area in the first surface 22a and the opening area in the second surface 22b are different in at least one of the plurality of through holes 22c. In this case, the lattice portion 22 may be formed with through holes 22c having the same opening area on the first surface 22a and the opening area on the second surface 22b. Moreover, either the opening area in the 1st surface 22a and the opening area in the 2nd surface 22b may be large, and any may be small.

Here, the opening area on the first surface 22a and the opening area on the second surface 22b are defined as follows. The surface of the first surface 22a is the first reference surface, and the surface of the second surface 22b is the second reference surface. Since the first surface 22a and the second surface 22b are parallel to each other, the first reference surface and the second reference surface are also parallel to each other. In addition, when some unevenness | corrugation is formed in the 1st surface 22a and the 2nd surface 22b by manufacturing error etc., the surface except the said unevenness | corrugation is made into the 1st reference plane and the 2nd reference plane. The openings of the through holes 22c in the first reference surface and the second reference surface are defined as the openings of the through holes 22c in the first surface 22a and the second surface 22b, and the opening areas are defined as the first surface 22a and the second surface 22b. The opening area at.

As described above, in the lattice body 21 according to the present embodiment, when used in the electrode plate of the lead storage battery 1, the active material is held in the first surface 22a, the second surface 22b, and the plurality of through holes 22c. However, since the first surface 22a and the second surface 22b are parallel to each other, the active material tends to fall off from the first surface 22a and the second surface 22b. However, since the opening area of the first surface 22a and the opening area of the second surface 22b are different in at least one of the plurality of through holes 22c penetrating the first surface 22a and the second surface 22b, the active material is a through hole. It becomes difficult to drop off 22c. Thereby, falling off of the active material can be suppressed.

In addition, in the lead storage battery 1 according to the present embodiment, since the lattice body 21 is used as the positive electrode lattice body 12 and the negative electrode lattice body 14, it is possible to suppress the positive electrode active material 13 and the negative electrode active material 15 from falling off.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in all of the plurality of through holes 22c, the opening area on the first surface 22a and the opening area on the second surface 22b may be different. In this case, the through-hole 22c in which the opening area on the first surface 22a and the opening area on the second surface 22b are the same is not formed in the lattice portion 22. Further, like the lattice portion 22B of the lattice body 21A of the modified example shown in FIG. 7, the through hole 22c in which the opening area on the first surface 22a is larger than the opening area on the second surface 22b, and the first surface 22a The through-hole 22c in which the opening area in is smaller than the opening area in the second surface 22b may be mixed. Thus, in all of the plurality of through holes 22c, the opening area of the first surface 22a and the opening area of the second surface 22b are different, so that the active material can be further prevented from falling off.

Further, in all of the plurality of through holes 22c, the opening area on the first surface 22a may be larger than the opening area on the second surface 22b. In this case, the through hole 22c in which the opening area on the first surface 22a is smaller than the opening area on the second surface 22b is not formed in the lattice portion 22. Thus, in all of the plurality of through holes 22c, by making the opening area on the first surface 22a larger than the opening area on the second surface 22b, the lattice body 21 can be easily formed, By filling the active material from the first surface 22a side, the filling property of the active material into the lattice body 21 is improved.

Further, the total opening area of the plurality of through holes 22c on the first surface 22a may be larger than the total opening area of the plurality of through holes 22c on the second surface 22b. The total opening area of the plurality of through holes 22c in the first surface 22a is the sum of the opening areas in the first surface 22a of each through hole 22c, and the total opening area of the plurality of through holes 22c in the second surface 22b. The sum of the opening areas on the second surface 22b of each through hole 22c. In this case, as in the lattice portion 22A of the lattice body 21A shown in FIG. 7, the opening area in the first surface 22a is larger than the opening area in the second surface 22b, and the opening in the first surface 22a. The through-hole 22c whose area is smaller than the opening area in the second surface 22b may be mixed. Thus, the active material as a whole becomes the through hole 22c by making the total opening area of the plurality of through holes 22c in the first surface 22a larger than the total opening area of the plurality of through holes 22c in the second surface 22b. It becomes difficult to drop off.

Further, in the cross section in the direction perpendicular to the first surface 22a and the second surface 22b, the inner wall surfaces of the plurality of through holes 22c may be formed in a straight line, but the lattice of the modification shown in FIG. As in the lattice portion 22B of the body 21B, a recess 22d into which the active material enters may be formed on at least one inner wall surface of the plurality of through holes 22c. In this case, recesses 22d may be formed on all inner wall surfaces of the plurality of through holes 22c. Further, not only the concave portion 22d but also the convex portion may be formed, so that the whole surface may be formed as a concave / convex portion. The number, shape, size, and the like of the recesses 22d are not particularly limited, and can be set as appropriate as long as the active material can enter. As described above, the recess 22d is formed on at least one inner wall surface of the plurality of through holes 22c, and further, the recess 22d is formed on all inner wall surfaces of the plurality of through holes 22c. As a result, the active material enters the recess 22d. Thereby, it can further suppress that an active material falls off.

Further, in the cross section in the direction orthogonal to the first surface 22a and the second surface 22b, the inner wall surfaces of the plurality of through holes 22c may be formed linearly, but the lattice of the modification shown in FIG. Like the lattice portion 22C of the body 21C, at least one of the plurality of through-holes 22c includes a first tapered portion 22e that extends to the first surface 22a, and a second tapered portion 22f that extends to the second surface 22b. It is good also as having. The opening area on the first surface 22a and the opening area on the second surface 22b are increased as the inclination angle θ1 of the first taper portion 22e and the inclination angle θ2 of the second taper portion 22f are increased, or the first taper portion 22e. The larger the second taper portion 22f, the larger the size.

In this case, each of the plurality of through holes 22c, that is, all of the plurality of through holes 22c may have the first tapered portion 22e and the second tapered portion 22f. In the first taper portion 22e, the through hole 22c is inclined in a direction extending with respect to the first surface 22a and reaches the first surface 22a in a cross section orthogonal to the first surface 22a. Similarly, in the second tapered portion 22f, the through hole 22c is inclined in a direction extending with respect to the second surface 22b and reaches the second surface 22b in a cross section orthogonal to the second surface 22b. In addition, in the cross section in the direction orthogonal to the first surface 22a and the second surface 22b, the first taper portion 22e and the second taper portion 22f do not necessarily need to be linear as long as they are tapered as a whole. The shape may be curved or uneven. As described above, when at least one of the plurality of through holes 22c has the first tapered portion 22e and the second tapered portion 22f, the active material filled in the through hole 22c is changed to the first surface 22a and the second tapered portion 22f. The shape is widened on both sides of the surface 22b. That is, the active material has a shape that sandwiches the lattice portion 22C of the lattice body 21C from both sides of the first surface 22a and the second surface 22b. For this reason, it can further suppress that an active material falls.

By the way, in the positive electrode grid body, mudification (softening phenomenon) in which the connection between the active materials is weakened by repeating charge and discharge progresses. Does not occur. For this reason, the lattice body 21 may be used only as the positive electrode lattice body 12. Thereby, it can suppress efficiently that an active material falls.

DESCRIPTION OF SYMBOLS 1 ... Lead acid battery, 2 ... Battery case, 3 ... Lid, 4 ... Positive electrode terminal, 5 ... Negative electrode terminal, 6 ... Liquid stopper, 7 ... Electrode group, 8 ... Positive electrode pillar, 9 ... Positive electrode plate, 10 ... Negative electrode plate, DESCRIPTION OF SYMBOLS 11 ... Separator, 12 ... Positive electrode lattice body, 12a ... Lattice part, 12b ... Ear part, 13 ... Positive electrode active material, 14 ... Negative electrode lattice body, 14a ... Grid part, 14b ... Ear part, 15 ... Negative electrode active material, 16 ... Positive side strap, 17 ... Negative side strap, 21, 21A, 21B, 21C ... Lattice, 22, 22A, 22B, 22C ... Lattice, 22a ... First surface, 22b ... Second surface, 22c ... Through hole, 22d ... concave portion, 22e ... first taper portion, 22f ... second taper portion, 23 ... ear portion, θ1 ... inclination angle of first taper portion, θ2 ... inclination angle of second taper portion.

Claims

A grid containing lead used in the electrode plate of a lead-acid battery,
A first surface and a second surface parallel to each other;
A plurality of through holes penetrating the first surface and the second surface,
In at least one of the plurality of through holes, the opening area on the first surface is different from the opening area on the second surface.
Lattice body.
In all of the plurality of through holes, the opening area on the first surface and the opening area on the second surface are different.
The lattice body according to claim 1.
In all of the plurality of through holes, the opening area on the first surface is larger than the opening area on the second surface,
The lattice body according to claim 1 or 2.
A total opening area of the plurality of through holes in the first surface is larger than a total opening area of the plurality of through holes in the second surface;
The lattice body according to any one of claims 1 to 3.
A recess is formed in at least one inner wall surface of the plurality of through holes.
The lattice body according to any one of claims 1 to 4.
Recesses are formed on all inner wall surfaces of the plurality of through holes.
The lattice body according to any one of claims 1 to 4.
At least one of the plurality of through holes has a first tapered portion that extends to the first surface and a second tapered portion that extends to the second surface,
The lattice body according to any one of claims 1 to 6.
Each of the plurality of through holes has a first tapered portion that reaches the first surface while expanding, and a second tapered portion that reaches the second surface while expanding.
The lattice body according to any one of claims 1 to 6.
The lattice body according to any one of claims 1 to 8 is used as the lattice body of at least one of the positive electrode plate and the negative electrode plate.
Lead acid battery.
The lattice body is a positive electrode lattice body used for a positive electrode plate.
The lead acid battery according to claim 9.